It can, especially with suspended timber floors. These rely on airflow underneath, usually through air bricks or vents, to prevent damp and protect the floor timbers. When insulation is added, that ventilation needs to be maintained, not blocked.

Solid floors don’t need underfloor ventilation since there’s no void beneath them, though general room ventilation still matters for air quality.

A professional installer will maintain or improve airflow as required by building regulations, so insulation and healthy ventilation work together rather than against each other.